Blood vessel anastomosing auxiliary tool

ABSTRACT

A blood vessel anastomosing auxiliary tool consisting of a flexible hollow conduit having opening ends at the opposite ends thereof, and comprising, on the outer surface of the conduit, at least two bulky portions, a retrieving means for retrieving the conduit from within a blood vessel, and desirably a guide wire for guiding the conduit when it is inserted into a blood vessel, characterized in that the conduit has flexibility and self-restoring property, and the bulky portions are disposed on the conduit eccentrically, the use of the blood vessel anastomosing auxiliary tool permitting a quick and positive anastomosis between a bypassed blood vessel and a bypassing blood vessel while a blood flow remaining in a portion between the central and peripheral sides of the bypassed blood vessel is secured during a blood vessel bypassing operation, and further ensuring an unobstructed blood vessel anastomosing to allow an easier practicing operation (anastomosing) than those by conventional tools.

TECHNICAL FIELD

The present invention relates to a blood vessel anastomosing auxiliarytool, especially to a blood vessel anastomosing auxiliary tool to beused for coronary artery bypass operation or blood vessel bypassoperation practiced to treat coronary artery diseases.

BACKGROUND ART

It happens that arteriosclerosis or the like cause stenosis in the bloodvessel and that blood flow to the peripheral side can be hardly obtainor can not be obtained. In such cases, a bypass operation is practiced,to bypass the stenosis site of the patient's own artery, vein or anartificial blood vessel, and to anastomose the central side and theperipheral side of the vessel.

While practicing this blood vessel anastomosing, in order to obtain agood vision of the anastomotic site, in general, a method of pressingtemporarily both ends of the vessel to be anastomosed and to decrease orstop the bleeding from the anostomotic site, was taken conventionally.On the other hand, in case the stenosis site is not completely closed,as blocking blood flow during blood vessel anastomosing may causeadverse effects to the peripheral side, therefore, a method whereinblood flow is secured even during the anastomosing operation isanticipated.

The present inventors have disclosed previously a blood vesselanastomosing auxiliary tool having circular projections (correspondingto the bulky portions of the present invention) on a hollow conduit, asdescribed in Japanese Laid-Open Patent Application No. 11-335. Saidauxiliary tool consists of a hollow conduit comprising circularprojections (bulky portion) at the ends, and a filamentary retrievingmeans at the central part, having elasticity to self-restore the hollowconduit bent after it is inserted into a blood vessel.

The use of the above described anastomosing auxiliary tool, havepermitted to practice blood vessel anastomosing without completelyblocking the blood flow. However, said blood vessel anastomosingauxiliary tool is formed (disposed) so that the shaft center of theconduit (shaft center of the non-bulky portion) and the shaft center ofcircular cross section formed at the outer edge of the circularprojection (corresponding to the bulky portion of the present invention)in the shaft direction of said conduit, are to be substantially thesame. Therefore, when the bulky portion of said auxiliary tool isinserted into a blood vessel, as it is shown in FIG. 10, the spaceformed between the bulky portion and the inner wall of the artery bloodvessel to which the tool is inserted, was small, and this was sometimean obstacle when anastomosing blood vessel. That is, when anastomosingblood vessel to another one, when the space was small as shown in FIG.10, there was a disadvantage that the suture needle would touch theanastomosing auxiliary tool, which caused difficulty for anastomosing.

Furthermore, as for the anastomosing auxiliary tool described inJapanese Laid-Open Patent Application No. 11-335, there was a problemthat it was difficult to insert the hollow conduit into a blood vessel.That is, at the time of the operation, it was not easy to insert theabove hollow conduit directly into a blood vessel from the opening(incision) of the blood vessel. Therefore, it was necessary to ensurethe opening (of the blood vessel) to make the insertion easy.

Moreover, there were several points to improve as for the towing meansof the hollow conduit of the anastomosing auxiliary tool of thisinvention. That is, when retrieving the anastomosing auxiliary tool fromthe blood vessel after the anastomosis, it is necessary to hold thefilamentary towing means and to pull it. However, as it is made from afine string, it was sometimes difficult to hold it tightly or ithappened to drop off the end of the string. Therefore, in order to holdthe string or to confirm the end of the string or the like (or to fillout the necessary information), a tool wherein a small plate (tab) isattached on the other end of the string attached to the hollow conduithas also been devised. In this manner, by attaching a tab to the end ofthe string, it became easier to retrieve the hollow conduit from withinthe blood vessel. However, as the conventional tab was not designed tobe held tightly, it was difficult to hold it tight, and it slipped whenmoving or pulling the tab with forceps, and it took time to retrieve thehollow conduit (the anastomosing auxiliary tool) from within the bloodvessel.

The object of the present invention is to provide a blood vesselanastomosing auxiliary tool that has improved each of the abovementioned problems.

DISCLOSURE OF THE INVENTION

The present invention relates to the amelioration of the blood vesselanastomosing auxiliary tool described in above mentioned JapaneseLaid-Open Patent Application No. 11-335, and have resolved each of theabove mentioned problems of the blood vessel anastomosing auxiliary toolby the following means.

First, the present invention relates to a blood vessel anastomosingauxiliary tool consisting of at least: a hollow conduit having openingsat both ends, having flexibility and self-restoring property forinserting into a blood vessel; a blood leaking preventing means on theouter surface of said hollow conduit, preventing blood leaking from thespace formed between the external wall of said conduit and the innerwall of the blood vessel, when the hollow conduit is inserted into ablood vessel; and a retrieving means for retrieving said conduit fromwithin a blood vessel (constituent features of the present invention);and furthermore characterized by: said blood leaking preventing means is2 or more circular bulky portions disposed on the outer surface of theconduit; and at least 1 of said circular bulky portion is disposedeccentrically against conduit shaft.

Secondly, in addition to the above described constituent features of theblood vessel anastomosing auxiliary tool of the present invention, thepresent invention relates to a blood vessel anastomosing auxiliary tool,having a flexible guide wire for guiding said hollow conduit when it isinserted into a blood vessel, said guide wire having a higher elasticitythan the blood vessel to be inserted, a width being adjustable to beinserted into the lumen of the hollow conduit, and a length being morethan 1.2 times longer than the length of the hollow conduit (shaftdirection).

Third, the present invention relates to the blood vessel anastomosingauxiliary tool according to the above described constituent features ofthe blood vessel anastomosing auxiliary tool of the present invention,wherein one end of said retrieving means is attached to said hollowconduit, and to the other end is attached a tab, wherein a holdingauxiliary means and an tissue-binding auxiliary means are disposed.

First, the first aspect of the present invention will be explained indetail.

The characteristics of the blood vessel anastomosing auxiliary tool ofthe present invention is that the tool consists of at least: a hollowconduit having openings at both ends, having flexibility andself-restoring property for inserting into a blood vessel; a bloodleaking preventing means on the outer surface of said hollow conduit,preventing blood leaking from the space formed between the external wallof said conduit and the inner wall of the blood vessel, when the hollowconduit is inserted into a blood vessel; and a retrieving means forretrieving said conduit from within a blood vessel; wherein said bloodleaking preventing means is 2 or more circular bulky portions disposedon the outer surface of the conduit; and at least 1 of said circularbulky portion is disposed eccentrically against conduit shaft.

With the above described feature, “at least 1 of said bulky portion isdisposed eccentrically against conduit shaft”, it becomes possible topractice the anastomosing operation easier and with accuracy. In otherwords, by using a blood vessel anastomosing auxiliary tool wherein theshaft center of the bulky portion is disposed to be different from theshaft center of the conduit (FIGS. 1-9), compared to a blood vesselanastomosing auxiliary tool wherein the bulky portion are not disposedeccentrically on the conduit (FIGS. 10, 11), the space 5 formed betweenthe inner wall of the blood vessel 11 and the anastomosing auxiliarytool 1 (non-bulky portion 3 of the conduit between the 2 bulky portions)becomes larger (for example FIG. 1). Thus, the use of this tool permitsan easier quick and positive anastomosis between a bypassed blood vesseland a bypassing blood vessel while a blood flow remaining in a portionbetween the central and peripheral sides of the bypassed blood vessel issecured during a blood vessel bypass operation.

The statement “the bulky portions are disposed on the conduiteccentrically” means in the present invention, that the bulky portionsare formed on the conduit so that the shaft center of the conduit andthe substantial center of the circular form formed with the outer edgeof the circular bulky portion (hereinafter referred to as shaft centerof the bulky portion) are not the same.

By making the shape of the bulky portions circular, when the bloodvessel anastomosing auxiliary tool is inserted into a blood vessel,blood leaking from the dissected blood vessel to the side visible duringthe operation can be prevented and it will not injure the inner wall ofthe blood vessel. By this point of view, it is preferable that the crosssection vertical to the shaft direction of the conduit, formed with theouter edge of the bulky portion, has a circular shape substantively.

Furthermore, it is most preferable that it is a perfect circle or acircular shape close to a perfect circle such as shown in FIGS. 7 and 8,so that it is easy to insert into a blood vessel, and can supportequally the inside of a blood vessel. However, the substantiallycircular cross section is not necessarily limited to a perfect circle,and it has only to be a cross section so that the concept of shaftcenter could be imagined. For example, the circular arc of the upperhalf and the lower half of the cross section could be a different shape(for example FIG. 12).

Moreover, the periphery of said circular bulky portion is morepreferably to be 1.1-2.0 of the periphery of the hollow conduit.

Next, the second aspect of the present invention will be explained indetail.

The present invention relates to a blood vessel anastomosing auxiliarytool characterized by, in addition to said constituent features of theblood anastomosing auxiliary tool of the present invention, having aflexible guide wire 13 guiding said hollow conduit when inserting into ablood vessel; having a higher elasticity than the blood vessel to whichthe guide wire 13 would be inserted; the width being adjustable to beinserted into the lumen of the hollow conduit; and the length being morethan 1.2 times longer than the length of the hollow conduit (shaftdirection).

As for the blood vessel anastomosing auxiliary tool of the presentinvention, the guide wire 13 being inserted to the hollow conduit 12,the flexibility of the blood vessel anastomosing auxiliary tool 1becomes higher as a whole. As the diameter of the guide wire 13 issmaller than the diameter of the hollow conduit 12, it would be easierto insert the hollow conduit 12 than inserting it without the guide wire13, alone into a blood vessel. Especially, in many cases, it isconvenient to use the tool wherein the guide wire 13 is inserted intothe hollow conduit 12 in advance, and the ends of the guide wire 13 isprojected from the ends of the hollow conduit, because the (projected)guide ends are to be inserted into a blood vessel.

However, as there is some cases that the guide wire 13 is not necessary,it is possible to put the guide wire 13 and the hollow conduit 12 in thesame bag separately, to sterilize and to insert the guide wire 13 intothe hollow conduit 12 according to need. In addition, “a width beingadjustable” mentioned above, means that the guide wire 13 can freely beinserted, retrieved, go through the lumen of the hollow conduit 12, andmore specifically that the outer diameter of the guide wire 13 issmaller than the inner diameter of hollow conduit 12.

Next, the above described third aspect of the invention will beexplained in detail.

The present invention relates to a blood vessel anastomosing auxiliarytool, according to the above described constituent features of the bloodvessel anastomosing auxiliary tool of the present invention, wherein oneend of said retrieving means is attached to said hollow conduit, and tothe other end is attached a tab wherein a holding auxiliary means and atissue-binding auxiliary means are disposed.

The holding auxiliary means and the tissue-binding auxiliary means couldbe a means which serves as both holding auxiliary means andtissue-binding auxiliary means. As for means which serves as both aholding auxiliary means and an tissue-binding auxiliary means, athrough-hole formed on the tab could be exemplified.

Furthermore, for said through-hole, it is preferable that the diameteris between 1 and 5 mm, and it is formed at 0.5-10 mm from the edge ofthe tab.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1, 2 and 3 are schematic diagrams showing the shape of the bulkyportion of the blood vessel anastomosing auxiliary tool of the presentinvention.

FIG. 4 is a schematic diagram to show the inserting angle α and theretrieving angle β of said bulky portion.

FIG. 5 is a schematic diagram to show the shape and the size of theblood vessel anastomosing auxiliary tool of the present invention.

FIG. 6 is a schematic diagram to show the relation between the outerdiameter of the non-bulky portion: n₂ and the height of the bulkyportion: n₁ of the blood vessel anastomosing auxiliary tool of thepresent invention.

FIG. 7 is a schematic diagram showing a situation wherein a part of theouter edge of the bulky portion of the blood vessel anastomosingauxiliary tool of the present invention is touching the outer edge ofthe non-bulky portion.

FIG. 8 is a schematic diagram to show the bulky portion of the bloodvessel anastomosing auxiliary tool of the present invention, wherein theeccentricity is low.

FIG. 9 is a schematic diagram showing the twist level of eccentricitydirection lines of each bulky portion of the blood vessel anastomosingauxiliary tool of the present invention.

FIG. 10 is a schematic diagram to show the shape of the bulky portion ofthe conventional blood vessel anastomosing auxiliary tool.

FIG. 11 is a schematic diagram of the cross section, vertical to theshaft of the bulky portion of the conventional blood vessel anastomosingauxiliary tool.

FIG. 12 shows a cross section of the bulky portion of the blood vesselanastomosing auxiliary tool of the present invention, wherein the shapeof the arc of the upper half and the lower half is different.

FIG. 13 is a schematic diagram showing an example of a blood vesselanastomosing auxiliary tool having a guide wire 13 of the presentinvention.

FIG. 14 is a schematic diagram of the tab of a blood vessel anastomosingauxiliary tool of the present invention.

BEST MODE OF CARRYING OUT THE INVENTION

Concerning the blood vessel anastomosing auxiliary tool 1 of the presentinvention, in order to obtain a larger space for the suture needle topass when anastomosing blood vessel, the bulky portion 2 is disposedeccentrically on the hollow conduit 12 as described above (FIGS. 1-9),and when the eccentricity is larger, a higher effect can be obtained.That is, compared with the small eccentricity as shown in FIG. 8, it ispreferable that the eccentricity is larger, such as the one shown inFIG. 7. Especially, as shown in FIG. 7, when the eccentricity is largeand that a part of the outer edge 6 of the bulky portion 2 is touchingthe extrapolation line 19 of the outer edge 7 of the non-bulky portion3, when anastomosing blood vessel, not only a larger space for thesuture needle to pass may be formed but it is preferable because itcould be also effective for the hemostasis during the blood vesselanastomosing.

Further more, generally 2 bulky portions are disposed for bulky portion2, but in some cases, it is possible to dispose more than 2, for example3 bulky portions. In such case, at least 1 bulky portion 2 can bedisposed eccentrically, but when 2 bulky portions 2 exist, it ispreferable to dispose eccentrically both the 2 bulky portions 2. In casethat both 2 bulky portions 2 are disposed eccentrically, by forming anddisposing eccentrically each bulky portions substantially on the sameside of the conduit 2, the space 5 formed between the inner wall of theblood vessel 11 and the blood vessel anastomosing auxiliary tool 1 islarger, compared to when the bulky portions are not disposed on the sameside. For the statement “disposing eccentrically each bulky portions 2substantially on the same side of the conduit 12”, it is defined asfollows.

As shown in FIG. 9, the straight line connecting C₁, which correspondsto the shaft center of the conduit 3 and d₁ which is the shaft center ofthe bulky portion 2 is the eccentric direction line, and when m1 is theeccentric direction line of 1 bulky portion 2, m₂ is the eccentricdirection line of the other bulky portion 2, as it is shown in FIG. 9,it refers to a situation that the twist angle γ made by m₁ and m₂ iswithin ±45 degrees, but it is preferable that said angle is smaller,most preferably 0 degree.

Furthermore, as for the height n1 of the bulky portion, as it is shownin FIG. 6, when n₂ is the distance from the bottom surface 8 to theupper outer surface 9 of the non-bulky portion of the conduit (that isthe outer diameter of the non-bulky portion), and n₁ is the distancefrom the upper outer surface 9 to the uppermost surface 10 of the bulkyportion of the non-bulky portion (the height of the bulky portion), itis preferable that n₁/n₂ is between 0.20 and 3.0. When said n₁/n₂ isless than 0.20, the space 5 formed between the inner wall of the bloodvessel 11 and the blood vessel anastomosing auxiliary tool 1 (thenon-bulky portion 3 of the conduit between the 2 bulky portions) couldnot be large, and when n₁/n₂ exceeds 3.0, the flow volume running in theconduit would be too small.

As for the shape of the bulky portion 2, as it is necessary to retrievethe blood vessel anastomosing auxiliary tool from within a blood vesseljust before the blood vessel anastomosing is finished, it is preferableto be in a shape so that it doesn't injure the inner wall of the bloodvessel 11 or not to hook the suture when retrieving the tool.

As for a shape preferable for the bulky portion 2, a shape of drop (teardrop) can be exemplified. Examples of a shape of drop (tear drop)include: as shown in FIGS. 1, 4 and 6, when the 2 bulky portions 2 haveidentical shape, each of the bulky portion 2 being bilaterally symmetricagainst the shaft direction of the conduit; as shown in FIG. 2, when the2 bulky portions 2 have identical shape, each of the bulky portions notbeing bilaterally asymmetric against the shaft direction of the conduit;and as shown in FIGS. 3 and 5, when the shape of the 2 bulky portions 2are not identical. However, the shape of the bulky portion 2 of thepresent invention will not be limited to these figures.

Moreover, it is preferable that the interface (portion) of bulky portion2 and non-bulky portion 3 are connected with a curved line to besmoothly joined with the hollow conduit, to prevent touching the bloodvessel wall when inserting or retrieving the tool. In said bulky portion2, the inserting angle is α as it is shown in FIGS. 4 and 5, and theretrieving angle is β. The inserting angle α mentioned here, refers tothe angle made between the arc touching the blood vessel wall of thebulky portion 2 and the shaft of the non-bulky portion (conduit) 3,wherein said bulky portion 2 is at the side where the blood vesselanastomosing auxiliary tool 1 of the present invention is inserted intoa blood vessel (for example the coronary artery). The retrieving angleis the angle made between the arc of the bulky portion 2, touching withthe non-bulky portion (conduit) 3, wherein said arc of the bulky portion2 touches the blood vessel wall just before the retrieving of the bloodvessel anastomosing auxiliary tool 1 of the present invention fromwithin a blood vessel (for example the coronary artery).

Moreover, as for the inserting angle α, when the inserting angle α ofthe bulky portion shown in FIG. 4 exceeds 45 degrees, the hollow conduit12 would easily touch the blood vessel wall when retrieving the bloodvessel anastomosing auxiliary tool 1 from within the blood vessel,therefore, it is preferable to be between 1 and 60 degrees. On the otherhand, when the angle is smaller than 20 degrees, the total length of thehollow conduit 12 would be long, therefore it is more preferable for theinserting angle to be between 20 and 45 degrees. Moreover, when theretrieving angle β of the bulky portion shown in FIG. 4 exceeds 46degrees, the hollow conduit 12 would easily touch the blood vessel wallwhen inserting or retrieving the blood vessel anastomosing auxiliarytool into or from within the blood vessel, and when the retrieving angleβ is smaller than 19 degrees, the space 5 would be small, therefore itis preferable to be between 20 and 45 degrees.

As for the material of the bulky portion 2, any synthetic resin materialcan be used, but materials that would hardly injure the inner wall ofthe blood vessel, such as ethylene-vinyl acetate copolymer (EVA),polyamide, silicone and the like are preferable. The bulky portion canbe formed with different material from the non-bulky portion of theconduit, but it is preferable that it is made from the same materialwith non-bulky portion 3, and moreover it is preferable that both bulkyportion 2 and non-bulky portion 3 have a shore hardness determined byJIS (Japanese Industry Standard) around 20-80 D. When said hardness isbelow 50, the tube may easier kink in the blood vessel, and when it ishigher than 70 D, it may injure the inner wall of the blood vessel.

In FIG. 13, the blood vessel anastomosing auxiliary tool 1 using theguide wire 13 is shown, and in FIG. 14, the tab 15 to be used for theblood vessel anastomosing auxiliary tool 1 of FIG. 13 is shown. Theblood vessel anastomosing auxiliary tool 1 of FIG. 13 is mostly composedof the hollow conduit 12 and the guide wire 13.

For the blood vessel anastomosing auxiliary tool 1 of FIG. 13, it ispreferable that the guide wire 13 has a higher degree of elasticity thanthe hollow conduit 12. However, the guide wire 13 requires apredetermined elasticity when inserting into the blood vessel, but if itis too hard, it could injure the inner wall of the blood vessel,therefore, the shore hardness of said guide wire 13 is preferably to bebetween 30-80 D, more preferably 40-50 D. Moreover, as for the length ofthe guide wire 13, it would not possible to achieve said aim if it istoo short, but be disturbing and a loss if it is too long, therefore itis preferable to be 1.2-5 times longer than the length of the shaftdirection of the hollow conduit 12.

A towing string 4 to which tab 15 is attached to one end, is attached tothe central part 14 of the hollow conduit 12, a penetrating through-hole17 and an eyelet 18 are formed on the tab 15. Both sides of the guidewire 13 are inserted into the lumen of hollow conduit 12, projectingboth ends from both ends of the hollow conduit 12. Both ends of thehollow conduit 12 are swollen in a circular form, and these 2 bulkyportions 2 are formed with a smooth curve on both ends. One end of thetowing string 4 is attached to the central part 14 of the hollow conduit12, and the other end is attached to the eyelet 18 formed on tab 15.

Said guide wire 13 is made from polyamide resin, and has flexibility andself-restoring property just like the hollow conduit 12.

Said through-hole is preferable to be formed at a distance of 0.5-10 mmfrom the edge of tab 15 (d1 of FIG. 14), because it makes easy topractice the holding operation of tab 15, for example, it is possible tohold without opening largely the forceps, which is a holding tool.

Next, the example for the use of tab 15 of the blood vessel anastomosingauxiliary tool is described. When retrieving the blood vesselanastomosing auxiliary tool 1 from within the blood vessel, it isnecessary to hold the through-hole 17 with forceps and the like and topull the tab 15. By this way, it is possible to pull the towing string 4by holding it surely and to retrieve the hollow conduit from within theblood vessel. Furthermore, when practicing the A-C bypass operation, bytemporarily attaching the blood vessel anastomosing auxiliary tool inadvance by suturing it with a surgical suture to a tissue near the siteto be operated, it is possible to use it immediately and have no concernabout losing it. It would be easy to attach it temporarily by passingthe surgical suture through the through-hole formed on tab 15, and toattach to the tissue with 1 or 2 stitches.

Concerning the retrieving means, as it is shown in FIGS. 5 and 13, it ispreferable that it is a fine and strong string 4 attached at the centralpart of the non-bulky portion. Examples include a string with the shapeand size of a fishing line and the like, and the material being silk,polyamide, polyolefin and the like. Moreover, it can be a linear threadin a tubular form as described in Japanese Laid-Open Patent ApplicationNo. 2000-5185.

The present invention will be described in detail by the followingexamples.

EXAMPLE 1

The composition of the blood vessel anastomosing auxiliary tool 1 ofFIG. 5 consists of: the non-bulky portion 3 of the hollow conduit 12,made from polyurethane, wherein 2 bulky portions are formed near of eachend; and a surgical suture 4 made from silk 5-0 attached to the centralpart of said non-bulky portion 3. The inner diameter of the non-bulkyportion 3 is 0.7 mm, the outer diameter (n₂) is 1.0 mm, the length ofthe central part of the non-bulky portion L₁ is 10.0 mm, the length ofthe shaft direction of the bulky portion L₂ is 3.0 mm, and the height ofthe bulky portion n1 is 1.0 mm. The thickness of the non-bulky portionis 0.15 mm. The inserting angle α of the bulky portion is 45 degrees,the retrieving angle β is also 45 degrees, and the two angles are thesame in this example. Moreover, as it can be seen from the figure, boththe 2 circular bulky portions 2 are formed at the outer side of thecircular conduit 3, and both the 2 bulky portions are formed to besubstantially of same shape and size, and are bilaterally symmetricagainst the center line Y.

EXAMPLE 2

The composition of the blood vessel anastomosing auxiliary tool 1 ofFIG. 13 is as follows: the length of the shaft direction of the centralpart 14 of the hollow conduit 12 (the length excluding the bulkyportion) is 12.0 mm, the length of the shaft direction of one bulkyportion 2 is 2.5 mm. The whole hollow conduit is made from polyamideresin, and has flexibility and self-restoring property (that is, even ifbend by force, by releasing it, it would go back straight as it was byit self). The outer diameter of the bulky portion 2 is around 1.5 mm(the inner diameter is around 0.5 mm), the outer diameter of the centralpart 14 is around 0.7 mm (the inner diameter is the same as the bulkyportion). The outer diameter of the guide wire 13 is around 0.4 mm, thelength is 50.0 mm and it is made from polyamide resin just like thehollow conduit.

INDUSTRIAL APPLICABILITY

According to the present invention, a blood vessel anastomosingauxiliary tool having beneficial effects including the following pointscan be obtained:

1. By disposing the bulky portion eccentrically on the conduit, a largespace is formed between the inner wall of the blood vessel and theanastomosing auxiliary tool when anastomosing blood vessel, thus, thesurgical suture can pass easier compared to conventional tools.Therefore, the operation becomes easy and ensuring, and the time neededfor is reduced.2. As for the auxiliary tool of the present invention, the bulky portionand the non-bulky portion of the conduit are joined with a smooth curvedline in a shape of tear drop, therefore there is no concern aboutinjuring the lining of the blood vessel when inserting or retrieving thetool, and these operations can be practiced easily.3. By using the guide wire with the hollow conduit, the hollow conduitmay be inserted more easily into the lumen of the blood vessel.Furthermore, by disposing holding means or tissue-binding means to thetab attached to the hollow conduit, it is possible to pull the hollowconduit by holding it tightly, and also to prevent losing theanastomosing auxiliary tool beforehand.

1. A blood vessel anastomosing auxiliary tool, comprising: a hollowconduit having openings only at both ends, and having flexibility andself-restoring property for inserting into a blood vessel; a bloodleaking preventer to prevent blood leaking from a space formed betweenthe external wall of said conduit and an inner wall of the blood vessel,when the hollow conduit is inserted into the blood vessel; and aretrieving means for retrieving said conduit from within the bloodvessel, wherein said blood leaking preventer satisfies following (a) to(e): (a) said blood leaking preventer comprises first and second bulkyportions which are formed at both ends of said hollow conduit, each ofsaid first and second bulky portions having a diameter larger than thatof non-bulky portion of the hollow conduit; (b) the bulky portions aredisposed eccentrically with respect to a central axis of the hollowconduit; (c) a twist angle γ is within ±45 degrees, where the twistangle γ is a crossing angle made by a line m₁ and a line m₂, where theline m₁ is an eccentric line which formed by connecting a central axisof the hollow conduit and a central axis of the first bulky portion, andthe m₂ is an eccentric line which formed by connecting a central axis ofthe hollow conduit and a central axis of the second bulky portion; (d)an inserting angle α of the bulky portions is between 20 and 45 degrees;and (e) a retrieving angle α of the two circular bulky portions isbetween 19 and 45 degrees.
 2. The blood vessel anastomosing auxiliarytool according to claim 1, wherein the retrieving means for retrievingsaid conduit from within a blood vessel is a linear thread attached nearthe central part of the hollow conduit.
 3. The blood vessel anastomosingauxiliary tool according to claim 1, wherein the first and second bulkyportions of the blood leaking preventer have a cross section ofsubstantially elliptical shape along the axis of the hollow conduit. 4.The blood vessel anastomosing auxiliary tool according to claim 1,wherein one part of the outer edge of the first and second bulkyportions is touching the outer edge of the non-bulky portion.
 5. Theblood vessel anastomosing auxiliary tool according to claim 1, whereinn1/n2 is between 0.20 and 3.0, when n2 is a diameter of the non-bulkyportion, and n1 is the height of the first and second bulky portions.